drqt02()

subroutine drqt02	(	integer	M,
		integer	N,
		integer	K,
		double precision, dimension( lda, * )	A,
		double precision, dimension( lda, * )	AF,
		double precision, dimension( lda, * )	Q,
		double precision, dimension( lda, * )	R,
		integer	LDA,
		double precision, dimension( * )	TAU,
		double precision, dimension( lwork )	WORK,
		integer	LWORK,
		double precision, dimension( * )	RWORK,
		double precision, dimension( * )	RESULT
	)

DRQT02

Purpose:

 DRQT02 tests DORGRQ, which generates an m-by-n matrix Q with
 orthonornmal rows that is defined as the product of k elementary
 reflectors.

 Given the RQ factorization of an m-by-n matrix A, DRQT02 generates
 the orthogonal matrix Q defined by the factorization of the last k
 rows of A; it compares R(m-k+1:m,n-m+1:n) with
 A(m-k+1:m,1:n)*Q(n-m+1:n,1:n)', and checks that the rows of Q are
 orthonormal.

Parameters

[in]	M	M is INTEGER The number of rows of the matrix Q to be generated. M >= 0.
[in]	N	N is INTEGER The number of columns of the matrix Q to be generated. N >= M >= 0.
[in]	K	K is INTEGER The number of elementary reflectors whose product defines the matrix Q. M >= K >= 0.
[in]	A	A is DOUBLE PRECISION array, dimension (LDA,N) The m-by-n matrix A which was factorized by DRQT01.
[in]	AF	AF is DOUBLE PRECISION array, dimension (LDA,N) Details of the RQ factorization of A, as returned by DGERQF. See DGERQF for further details.
[out]	Q	Q is DOUBLE PRECISION array, dimension (LDA,N)
[out]	R	R is DOUBLE PRECISION array, dimension (LDA,M)
[in]	LDA	LDA is INTEGER The leading dimension of the arrays A, AF, Q and L. LDA >= N.
[in]	TAU	TAU is DOUBLE PRECISION array, dimension (M) The scalar factors of the elementary reflectors corresponding to the RQ factorization in AF.
[out]	WORK	WORK is DOUBLE PRECISION array, dimension (LWORK)
[in]	LWORK	LWORK is INTEGER The dimension of the array WORK.
[out]	RWORK	RWORK is DOUBLE PRECISION array, dimension (M)
[out]	RESULT	RESULT is DOUBLE PRECISION array, dimension (2) The test ratios: RESULT(1) = norm( R - A*Q' ) / ( N * norm(A) * EPS ) RESULT(2) = norm( I - Q*Q' ) / ( N * EPS )

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.